MISSING person Raphael Joseph was last seen in Auburn on March 20, 2014.

The 37-year-old man from Chiswick was reported getting into the back seat of a late model silver sedan in Dartbrook Road, Auburn, about 11.30pm.

Mr Joseph was previously known as Rafi Tooma and known as "Huss" or "Hussany" to his friends.

His family reported him missing on March 22 because they were unable to contact him.

They joined police at the launch of Missing Persons Week in the hope someone could come forward with new information about him.

Police said in the hours before his disappearance, Mr Joseph spent time in his Chiswick apartment and at a Pyrmont casino.

They believe Mr Joseph travelled to Auburn in a white 2009 E350 Mercedes with Tasmanian registration plates to meet someone at a fast food restaurant in Dartbrook Road, close to where he went missing.

The homicide squad is leading the investigation into his disappearance. The squad's commander, Mick Willing, said there were serious concerns for Mr Joseph.

"We don't know where Mr Joseph is but we believe he was kidnapped," Superintendent Willing said.

"We have spoken with many of his friends and associates, searched private properties, public spaces and bushland in hope of finding clues to his whereabouts.

"We are appealing for anyone who was in Dartbrook Road, Auburn, around 11.30pm on Thursday, March 20, who haven't spoken with police to get in contact with us."

Mr Joseph is described as being of Mediterranean or Middle Eastern appearance, with an olive complexion, 175-180 centimetres tall, with black hair and brown eyes.

At the time of his disappearance he was clean-shaven and wearing a grey T-shirt, khaki pants and dark shoes. Superintendent Willing said people could contact the police anonymously through Crime Stoppers.